Re: [PATCH v9 10/15] ovl: A new xattr OVL_XATTR_METACOPY for file on upper

[Vivek Goyal <vgoyal@redhat.com>]

On Mon, Jan 08, 2018 at 04:50:00PM +0100, Miklos Szeredi wrote:
> On Wed, Nov 29, 2017 at 4:54 PM, Vivek Goyal <vgoyal@redhat.com> wrote:
> > Now we will have the capability to have upper inodes which might be only
> > metadata copy up and data is still on lower inode. So add a new xattr
> > OVL_XATTR_METACOPY to distinguish between two cases.
> 
> Maybe I missed something, but I think there's a bug in this patch:
> truncate() is a metadata+data operation since it affects results of
> read().  So it should be handled by doing the data copy-up like we did
> before.

Hi Miklos,

For truncate operation, we don't do metadata only copy up and fall back
to regular operation.

ovl_need_meta_copy_up() {
        if (flags && ((OPEN_FMODE(flags) & FMODE_WRITE) || (flags & O_TRUNC)))
                return false;

}

So behavior should not change with metacopy for truncate operation.

Am I missing something?

Thanks
Vivek